Web 2.0 at my library

Our city has a lot of programs for seniors. Not just library programs or rec department programs but also transportation, health, housing etc. Some of these are offered by city departments and some by non profits. We have a group that meets monthly of representatives from organizations that serve seniors. One of the issues that comes up is that, although we have lots of services, we also have many seniors who do not know about them. So, since the library is 'information central', I've been thinking about how we could help solve that problem using web 2.0 tools. Maybe a listserv would work. At first I though a website or a blog but that is too one-way. With a listserv, seniors could post as well as organizations with programs or events to announce. I realize that many seniors are not online but I believe that is changing rapidly and now would be a good time to initate something. We have listservs of parents at the schools, why not one for seniors.